The malleability of neuronal circuits by environmental conditions is a crucial property in developing brain in fostering adaptive development of perceptual and behavioral faculties. This is particularly obvious in sensory systems. Brainstem taste pathway is potentially a suitable model system to understand competitive interactions and activity dependent reorganization, two possible mechanisms of neuronal malleability, also termed plasticity. Understanding the mechanisms of plasticity is a major step in developing strategies to avoid developmental defects, and to foster normal development of the brain function. A research program is designed to determine whether taste circuits have cellular and molecular components that may allow sensory systems to undergo changes during deviations from normal environmental stimuli. The first study aims to obtain evidence for whether distinct gustatory nerves converge upon individual neurons, using a combination of anterograde and retrograde tract-tracing anatomy, confocal microscopy using multiple markers and electron microscopy. How and when in development such input convergences occur will have important outcomes for our understanding of the role of competitive interactions in plasticity. The second aim of the proposed project will examine fine structure and glutamate receptor signature of axons that are destined to withdraw during development of taste pathways. The potential findings of the proposed experiments shall provide novel information on target selectivity of two gustatory nerves, as well as underlining gustatory afferent development as a model to study developmental plasticity and lifelong synaptic stability.